'67 327/300 Valve cover gasket and adhesive?

[Kevin G.]

While attempting to install new spark plugs in my '67, to my surprise it appears the heads may have been swapped at some point before my ownership. The cylinder heads accepted only the small "peanut" spark plugs.....?

I ran a search here and found some great info, simply a confirmation thread....

I'm going to pull off the valve covers to reveal the casting and date numbers, and now researching what gaskets and adhesive I should use?

I have read there are a thinner 5/32" and 7/32" cork gasket, both available at my local Napa store. Most replies I read suggested using the thinner of the two. But not conclusive recommendation on the adhesive, several opinions with differing preferences.

Thanks in advance for the advice!

[John F.]

Re: '67 327/300 Valve cover gasket and adhesive?

Use the thick cork gaskets. Make sure valve covers are not bent. Do not overtighten the bolts.

[Joe L.]

Re: '67 327/300 Valve cover gasket and adhesive?

While attempting to install new spark plugs in my '67, to my surprise it appears the heads may have been swapped at some point before my ownership. The cylinder heads accepted only the small "peanut" spark plugs.....?

I ran a search here and found some great info, simply a confirmation thread....

I'm going to pull off the valve covers to reveal the casting and date numbers, and now researching what gaskets and adhesive I should use?

I have read there are a thinner 5/32" and 7/32" cork gasket, both available at my local Napa store. Most replies I read suggested using the thinner of the two. But not conclusive recommendation on the adhesive, several opinions with differing preferences.

Thanks in advance for the advice!

Kevin-------

My preference for years has been Fel-Pro cork-lam gaskets, the thicker gaskets with a steel core. The cork on these gaskets is "rubberized.

[Kevin G.]

Re: '67 327/300 Valve cover gasket and adhesive?

Use the thick cork gaskets. Make sure valve covers are not bent. Do not overtighten the bolts.

Thank you John!

[Kevin G.]

Re: '67 327/300 Valve cover gasket and adhesive?

Kevin-------

My preference for years has been Fel-Pro cork-lam gaskets, the thicker gaskets with a steel core. The cork on these gaskets is "rubberized.

Thank you Mr Lucia! On my way to the store now. As for the adhesive?

[Joe L.]

Re: '67 327/300 Valve cover gasket and adhesive?

Thank you Mr Lucia! On my way to the store now. As for the adhesive?

Kevin------


I use 3M weatherstrip adhesive on the valve cover side and nothing on the cylinder head size. This allows for the removal of the valve covers without the need for replacement of the gaskets. Usually, it seals fine. However, if you are really paranoid about leaks you can use a oil-resistant sealer like Ultra Black on both sides of the gaskets. If so, apply sparingly.

As John mentions, your steel valve covers need to be straight. Make sure to flatten the covers at each bolt hole.

To really help guard against leaks it's a good idea to use the load spreading style retainers once used by GM on Corvair engines. These will definitely appear non-original if that's your intention but they greatly improve sealing on small block steel valve covers.

[John F.]

Re: '67 327/300 Valve cover gasket and adhesive?

I use a little PAM cooking spray on the gasket/head side.

[Kevin G.]

Re: '67 327/300 Valve cover gasket and adhesive?

John and Joe……

Tip my hat to you for the advice!

Only the Felpro rubberized cork sets were in stock. I bought both thicknesses. I’ll also be ordering the cork-lam as recommended. My shopping bag also included the Ultra Black Permatex.

Next, to get to those dates and numbers! New heads just might be next on the list….?

Again, thank you!

[Terry M.]

Re: '67 327/300 Valve cover gasket and adhesive?

Kevin,

I agree with what the others said. You'll want to make sure your valve cover gasket surfaces are flat. Not unusual for them to be deformed at the bolt holes. Easy enough to do with a little hammer work. As for adhesive, I only use 3M weatherstrip adhesive, and only on the valve cover surface. I submitted a TDB post on January 1, 2021 under "Re: Fel Pro Valve Cover Gasket" that outlined my process for installing the gasket to the cover. I have done many valve cover gaskets this way over the years and it has always worked well for me. Another trick I use in tightening the cover down...first snug the cover bolts down; then, using a wide, narrow piece of wood (small piece of lath, for example) go around the rail, gently tapping the end of the wood to help further seat the gasket. You should then be able to tighten the bolts a bit more. The key is to not overtighten and deform the valve cover metal. Of course, with aluminum valve covers, the issue is not the same due to the rigid nature of the cover...they don't distort.

Good Luck.

Terry

[Kevin G.]

Re: '67 327/300 Valve cover gasket and adhesive?

Kevin,

I agree with what the others said. You'll want to make sure your valve cover gasket surfaces are flat. Not unusual for them to be deformed at the bolt holes. Easy enough to do with a little hammer work. As for adhesive, I only use 3M weatherstrip adhesive, and only on the valve cover surface. I submitted a TDB post on January 1, 2021 under "Re: Fel Pro Valve Cover Gasket" that outlined my process for installing the gasket to the cover. I have done many valve cover gaskets this way over the years and it has always worked well for me. Another trick I use in tightening the cover down...first snug the cover bolts down; then, using a wide, narrow piece of wood (small piece of lath, for example) go around the rail, gently tapping the end of the wood to help further seat the gasket. You should then be able to tighten the bolts a bit more. The key is to not overtighten and deform the valve cover metal. Of course, with aluminum valve covers, the issue is not the same due to the rigid nature of the cover...they don't distort.

Good Luck.

Terry

Hi Terry, I believe it was your older post that I read while searching! Thank you!

I do have some of the yellow boogie glue on the shelf! 😆

[Edward J.]

Re: '67 327/300 Valve cover gasket and adhesive?

Hi Terry, I believe it was your older post that I read while searching! Thank you!

I do have some of the yellow boogie glue on the shelf! 

Kevin, not sure if the factory bolts will be long enough with the thicker gaskets if your engine is using the tin covers you may want to use the thinner gaskets.

[Duke W.]

Re: '67 327/300 Valve cover gasket and adhesive?

I use a little PAM cooking spray on the gasket/head side.

I use silicone spray lube. Vegetable oil will oxidize at relatively low temps. Silicone is stable to at least 400F. This is probably more important on mechanical lifter engines since they require periodic valve clearance checks, and the above should allow the gaskets to be reused 1-3 times.

OP: Do not overtighten the valve cover cap screws. Too much torque will distort the thin steel and lead to leaks. I believe the torque spec is 25 INCH-pounds, but check your service manual. Torque them up evenly in two to three increments and retorque after a few heat cycles. Don't loosen, just apply the proper torque. Repeat after a few more heat cycles until the cap screws no longer tighten with the correct applied torque.

There are a wide variety of gasket cements. A knowledgeable parts counter guy should be able to direct you to a decent one.

If you're in the judging process, use cork. If not use what Joe recommends.

Duke

[Larry E.]

Re: '67 327/300 Valve cover gasket and adhesive?

Kevin: I come from the "Old School". I have use the below for years. It can be messy so
go slow and it will come out well. JMHO>Larry

[Mark E.]

Re: '67 327/300 Valve cover gasket and adhesive?

Indian Head works well and is easy to spread.

I'm surprised weatherstrip adhesive doesn't liquidity at engine temperatures...but apparently works for some guys.

My experience is synthetic oil saturates then eventually seeps through cork gaskets. Don't know about cork lam or rubberized cork, but avoid cork if you plan to run synthetic oil.